Portable signs were the visual bane of many communities in the United States in the 1980s and 1990s. Today, except in perpetually 20-years-behind-the-times suburban Buffalo, and classic "towns next door" of a more RUGGED! nature, portable signs are a far less common blight on the American landscape than they used to be 15 or 20 years ago. Many communities ban them altogether, and a growing number of communities are enacting bans.
When I cross the border to Canada, though, it seems like it's 1990 all over again, at least when it comes to portable signs. They're everywhere in communities in the Golden Horseshoe. Several years ago, Nerudite posted photos of strip commercial areas in the Edmonton area, many showing multiple portable signs.
Portable signs in Canada take a somewhat different form than those south of the border. In the US, the remaining signs take the form of the classic "reader board", many with a top-mounted arrow. The background is usually white or off-white; the changeable copy black. In Canada, the background of portable signs is usually black, with the changeable copy being white and fluorescent colored.
In the Buffalo area, I've seen both American-style white and Canadian-style black portable signs. I haven't seen the Canadian-style portables anywhere else in the US.
So, Canadian Cyburbians: why do you think portable signs might be more common north of the border?